Downloaded and upgraded to RC1 today, and now RoundCube does not work in Firefox 2.0.0.7. Works fine in IE.
The symptons are that nothing happens when I press a button. E-Mail, Address Book, Personal Settings and Logout seems to work, but buttons/link to inbox, drafts, sent, junk, trash, compose etc does not work. Nothing happens. It's the same for Save, Folders and Identities when I go into Personal Settings.